Espio the Chameleon is an purple anthropomorphic chameleon and an expert ninja. Espio’s name is thought to either have come from the word “espionage”, another word for spying, or to be a reference to the Spanish word “espio” (meaning literally “I spy”).
Espio first appeared in Knuckles’ Chaotix (simply Chaotix in Japan) for the Sega 32X. The Japanese manual states that Espio, being a detective, goes to investigate the mysterious island that has emerged from the sea.
In the American manual, he is a friend of Knuckles the Echidna, and is visiting “Carnival Island” when Robotnik attacks it.
In both cases, he is attacked by Doctor Robotnik and Metal Sonic who try to capture him. Knuckles saves him from the two, and Espio automatically becomes his partner character for the training stage. After this, Espio can be chosen in the “Combi-Confiner” prior to stages. Espio can walk on walls and ceilings, and uses his own Whirl Attack instead of the common Spin Attack.